Electronic products generally required for the directly supply from the power supply cables, but due to the limitation of the power supply cables, leads to the inconvenience in mobility of electronic products. Therefore, plenty of low-power electronic products use rechargeable batteries for powering, but the rechargeable batteries also need to use the contact point or plug for cable charging. However, the current cable charging method often unable to charge because of the dirty, wear-and-tear of the contact chips, even more the poor contact between the contact points may cause point discharge effect, which will burn out the electronic products or even cause security incidents. And there are also some electronic products that are not applicable to the cable powering or charging, such as water-proof electronic products, human body portable electronic devices, oral-style medical diagnostic equipments, the cell phone and game control units which require frequent usage and charging.
At present, many domestic and foreign enterprises have already introduced the non-contact charging products, but there are still many inadequacies in the product performance and capacity, firstly, the transmission distance is extreme short and range is very small, both the transmitter and the receiver must be closed with each other to work out; secondly, the phase terminal of the transmitting and the receiving coils must be the same, so the receiver cannot be placed in any directly; thirdly, it requires to constitute a resonance relationship between power supplier and power receiver, so as to carry out the power transmission, in this way it could only be a one to one transmission; fourthly, the power transmission is limited, so it could only be used for battery charging by small current.